A liquid crystal display (LCD) device includes a backlight driving circuit, and a backlight driving circuit that uses a light emitting diode (LED) as backlight source is called a LED backlight driving circuit. The LED backlight driving circuit includes an LED light bar and a constant current driving chip that drives the LED light bar. A typical constant current driving chip has a short-circuit protection function. A comparator is connected with a cathode end of each of the LED light bars, and the comparator compares voltage of the cathode end of each of the LED light bars with a reference voltage. If the voltage of the cathode end of the LED light bar is greater than the reference voltage, a corresponding LED light bar turns off, and if the voltage of the cathode end of the LED light bar is less than the reference voltage, the corresponding LED light bar is in normal operation.
Voltages of one or more LED light bars are great, and far exceed voltage of remaining normal LED light bars, however, the constant current driving chip turns off remaining normal LED light bars instead of turning off abnormal LED light bars.